Psychological research has found that women score higher on most measures of the traits, motivations, and values that predict helping others, and women are more likely to help family and friends. However, sex differences in the institutional helping behaviors of volunteering and charitable giving are small. This paper seeks to explain this apparent contradiction with the hypotheses that men have more resources and more social capital than women, which compensates for their lower level of motivation. The paper tests these hypotheses using data from the 1995 Midlife in the United States (MIDUS) survey. The data show partial support for these hypotheses, as men score higher on measures of income, education, trust, and secular social networks. However, women have broader social networks through religious participation.